The invention relates to an X-ray device, comprising an X-ray tube and an image intensifier/pick-up chain, including an X-ray image intensifier, an image pickup system with a first and a second image sensor, an image processing system, and an optical beam splitter which is arranged between the image intensifier and the image pick-up system in order to image an exit screen of the image intensifier on the image sensors.
2. Description of the Related Art
An X-ray device of this kind is known from DE A 33 15 883.
An X-ray device disclosed in the cited Patent Application is used to form images of an object, for example a patient, present between the X-ray source and the image intensifier/pick-up chain. An optical beam splitter is used to enhance the spatial resolution. This optical beam splitter images an exit screen of the image intensifier on two or more image sensors.
The number of images picked up by means of the image sensors in an X-ray system is dependent inter alia on the exposure time, the integration time, the readout time and the image processing system used. The exposure time is determined by the absorption within the patient and by the desired signal-to-noise ratio of the image. The integration time is determined by the conversion of the optical image into an electric charge by the sensor and is dependent on the sensitivity of the sensor and the amount of light from the image intensifier. The read-out time is determined by the reading of the electronic information of the sensor, for example a CCD sensor or Vidicon, for supply to an image processing system. The minimum read-out time for an image sensor of given technology is fixed. The maximum number of images to be picked up per second is determined by this minimum read-out time, and hence also the rate at which an image processing system connected thereto can process these images.
The main drawback of the known device consists in the inherent limitation of the pick-up speed, because the maximum number of images that can be picked up by a sensor per second is limited. A second drawback consists in that motion artefacts occur in the image when quickly moving objects are picked up.